11,421 research outputs found
Electromagnetic and gravitational radiation from the coherent oscillation of electron-positron pairs and fields
Integrating equations of particle-number and energy-momentum conservation and
Maxwell field equations, we study the oscillation and drift of electron and
positron pairs coherently with fields after these pairs are produced in
external electromagnetic fields. From the electric current of oscillating
pairs, we obtain the energy spectrum of electromagnetic dipole radiation. This
narrow spectrum is so peculiar that the detection of such radiation can
identify pair production and oscillation in strong laser fields. We also obtain
the energy spectrum of gravitational quadrapole radiation from the
energy-momentum tensor of oscillating pairs and fields. Thus, we discuss the
generation of gravitational waves on the basis of rapid development of strong
laser fields.Comment: 6 pages, 4 figure
Highly efficient interfacing of guided plasmons and photons in nanowires
Successful exploitations of strongly confined surface plasmon-polaritons
critically rely on their efficient and rapid conversion to lossless channels.
We demonstrate a simple, robust, and broad-band butt-coupling technique for
connecting a metallic nanowire and a dielectric nanofiber. Conversion
efficiencies above 95% in the visible and close to 100% in the near infrared
can be achieved with realistic parameters. Moreover, by combining butt-coupling
with nanofocusing, we propose a broad-band high-throughput near-field optical
microscope.Comment: 5 figure
Coherent interaction of a metallic structure with a single quantum emitter: from super absorption to cloaking
We provide a general theoretical platform based on quantized radiation in
absorptive and inhomogeneous media for investigating the coherent interaction
of light with metallic structures in the immediate vicinity of quantum
emitters. In the case of a very small metallic cluster, we demonstrate extreme
regimes where a single emitter can either counteract or enhance particle
absorption by three orders of magnitude. For larger structures, we show that an
emitter can eliminate both scattering and absorption and cloak a plasmonic
antenna. We provide physical interpretations of our results and discuss their
applications in active metamaterials and quantum plasmonics
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